London



smza. @a haommz SR A. T. DAWSON AND G. L BUCKHAM. SIGHTING APPARATUS ron ANTI-AIRCRAFT Guus'.

. APlLCATIUN FILED IUNE 2|. 2911. 1,304,272. Patented May 20, 1919.

y 2 SHEETS-SHEET Il.

A. T.MDAWS0N AND G. T. BUCKHAM. SIGHTING APPARATUS Fon ANTI-Mmmm Guus.

APPLICATION FILED IUNEZI- IQH Patented May 20,1919.

2 SHEETS-$115111 2 InvenTors Rvfhur T D a wson @Gear UNITED STATES PATENT OFFICE.

ARTHUR TREVOR DAWSON AND GEORGE THOMAS BUCKI-IAM, OF WESTMINSTER, LONDON, ENGLAND, ASSIGNORS TO VICKERS LIMITED, OF WESTMINSTER,

LONDON, ENGLAND.

SIGI-I-TING APPARATUS FOB, ANTI-AIRCRAFT GUNS.

Specification of Letters Patent.

Patented May 20, 1919.

Application led June 21, 1917. Serial No. 176,114.

To all whom it may concern.'

Be it known that we, Sir ARTHUR TREvoR DAwsoN, knight, and Sir GEORGE` THOMAS BUCKHAM, knight, both subjects of the -King of Great Britain, residing at Vickers House, Broadway, Westminster, in the county of London, England, have invented certain new and useful Improvements in or Relating to Sighting Apparatus for Anti- Aircraft Guns, of which the following is a specification.

This invention relates to sighting apparatus for anti-aircraft guns in which means j are provided whereby the deflectionkrsetting j of the sight in accordance with the speed at which the target is moving relatively to the y gun, is automatically corrected for the varying angles of sight during the elevation and depression of the gun.

According to the invention the aforesaid correction is eected by means which are capable of adjustment in accordance with the ascertained height of the target, so that after this adjustment has been made the act of elevating or depressing the gun to keep the sight on the target automatically corrects the deection angle for the changing angle of sight and for the changing range without its being necessary to ascertain the range. The said means preferably comprise a cam which is mounted on the carriage and is capable of being set angularly in accordance with the height of the target.

In order that the said invention may be clearly understood and readily carried into effect, we will describe the same more fully with reference to the accompanying drawings, in which Figure 1 is a side elevation showing sighting apparatus provided with one form of the means for automatically varying the deflection of the sight in the vertical plane in accordance with the height of the target and the angle of sight.

Fig. 2 is a section taken approximately on the line 2, 2 of Fig. 1.

Fig. 3 is a view similar to Fig. 1 but showing the sighting apparatus provided with means for automatically varyin the deflection of the sight in both the vertical and the horizontal plane.

Fig. Sais a plan viewed at right angles t0 the sight bar B of Fig. 3 showing the means for automatically varying the deflection of the sight in the horizontal plane.

Fig. 4 is a side elevation showing sighting apparatus provided with another form of the means for automatically varying the deflection of the sight in the vertical plane.

Fig. 5 is a section taken approximately on the line 5, 5 of Fig. 4, and

Fig. 6 is a section taken approximately on line 6, 6 of Fig. 5.

A is part of the gun carriage and A is the gun cradle trunnioned to the gun carriage. B is the sight bar which in the examples shown carries open sights, and B is the sight arm pivoted to a bracket A2 on the gun cradle. C is the cam which is adjustably mounted on the gun carriage and serves to vary automatically the vertical deflection of the sight bar.

In the construction shown by Figs. 1 and 2, the sight bar B has a pivot b pivotally mounted in the bracket A2 and the sight arm B is pivoted upon the portion of the said pivot situated between the bracket A2 and the sight bar as will be seen from Fig. 2. The cam C is pivotally mounted on the gun carriage and its angular position is adjusted in accordance with the height of the target by a worm C carried 'by a shaft C2 which is angularly displaced by the handle appertaining to the height setting mechanism of the sighting apparatus for causing the angle of tangent elevation to be automatically corrected during the elevation of the gun. Part of the cam of this height setting mechanism is indicated by the chain line E. Arranged in contact with the cam C is a roller D carried by one arm of a lever D pivoted at d to the bracket A2; the other arm of this lever engagesl with a stud or projection d on a member D2 slidably mounted in a longitudinal guide b on the sight arm B. The said member D2 carries near its forward end a bracket cl2 formed with a slot Z3 which is situated transverse to the guide b and in which is slidably disposed a block or nut D3; with this nut engages a screw Z4 which is carried by the bracket Z2 and is adapted to be actuated through suitable gearing by a handwheel DL1 carried by the sliding member D2. The said block or nut D3 is formed with a pin or lprojection Z5 (see Fig. 2) carrying a block D5 disposed in a slot B2 formed longitudinally in the sight bar B. Attached to the sight bar B is a verticaldeflection scale ZG graduated in accordance with the vertical components of the relative yspeed of the target and attached to the block or nut D3 is a pointer or index member Z7 situated contiguous to the said scale D. The sight arm B carries at its forward end a roller BX bearing against the aforesaid cam E. It will be clear that rotation of the screw Z4 by the handwheel D4 will angularly displace the sight bar B relatively to the sight arm B so that the slot B2 then assumes an inclined position with respect to the guide ZJ of the sight arm B. If the gun be then elevated, the roller D will move in contact with the cam C which has previously, as aforesaid, been adjusted in accordance with the height of the target, and in consequence the member D will move along its guide Z9 carrying with it the block or nut D3. The block D5 will therefore move along the slot B2 which as aforesaid is then at an angle to the guide o and in consequence the vertical deflection imparted by the handwheel D4 will be automatically Varied in accordance with the height of the target and the angle of sight. If on the other hand the gun is elevated prior to any initial adjustment for vertical deflection having been made the dista-nce of the aXis of the roller D5 from the axis of the pivot Z) will be altered during the elevation of the gun so that when the handwheel D* is operated to bring the pointer Z7 opposite the graduation on the scale ZG corresponding to the vertical component of the speed of the target, the angular displacement of the sight bar B relatively to the sight arm B will vary in accordance with the position of thc roller D5, that is to say in accordance with the height of the target and the angle of sight. So long as the pointer Z7 lies opposite the zero mark of the scale ZG (which is the position shown in Fig. l) the slot B2 will be situated parallel to the guide b and the sight bar will therefore not be displaced relatively to the sight arm when the memloer D2 is moved along its guide o during the elevation of the gun.

A similar arrangement to that above described for obtaining the automatic variation of the vertical deflection may also be employed for obtaining the automatic variation of the horizontal deflection. Fig. 3 shows sighting apparatus provided with such an arrangement in addition to the arrangement shown by Figs. 1 and 2 for obtaining variation of the vertical deflection. In this ligure the automatic variation of the horizontal deflection is obtained by an additional cam C* and an additional lever DX operating to impart change of horizontal deflection to the sight bar B in the same manner as described with reference to Figs. l and 2 in connection with the vertical deflection. D4X is the handwheel appertaining to the horizontal deflee-tion gear. In Fig. 3 the sight arm B has a member D2 slidably mounted thereon which carries the vertical deflection gear described with reference to Fig. 2. The block D of this gear operates by means of the slot B2 upon a bar B2X which therefore receives the same motionsv as the bar B in Fig. 2. The sight bar B is pivoted to the rear part of the bar BLX for lateral movements. The bar B2X has slidably mounted thereon a member D2X which is operated by the lever DX and carries the horizontal deflection gear comprising a block B4XX similar to the block D5 working in a slot Bo in the sight bar B in a similar manner to that described with reference to the vertical deflection gear.

In the form of the invention shown by Figs. 4.-, 5 and 6 the sight arm B has mounted thereon a swinging bracket B3 having a guide in which a member b3 is slidably disposed. This member hasf a pin b4 upon which is pivotally mounted a block B4 slidably disposed in a longitudinal slot 57 formed in a bar B5 which may constitute the sight bar itself or may have the sight bar pivoted thereto for horizontal deflection movements in which case the bar B5 would carry the horizontal deflection gear. The swinging bracket B3 is connected to one end of a link B6 the other end of which is slidably disposed in a guide B7 having a pivot Z)7 pivoted to the bracket A2 referred to in the description of Figs. l and 2. Pivoted upon the said pivot between the guide B7 and the bracket Az are the sight arm B and the bar B5. The said link B6 carries a roller b4 lying in contact with the cam C which in this case instead of being pivoted is mounted to slide in a curved guide AX on the gun carriage. The cam C is adjusted in accordance with the height of the target by a cam F on the shaft C2 referred to in the description of Fig. 1. The swinging bracket B3 has a graduated scale ZG and the pin b4 carries a pointer (Z7 as described with reference to Figs. l and 2. The handwheel D4 for imparting vertical deflection to the sight to agree with the vertical component of the relative speed of the target, is mounted on a shaft carried by the bracket B3 and connected by bevel gearing to a worm Do gearing with teeth on the sliding member 3. By rotating the handwheel D4 the sliding member o4 is moved along the guide in the bracket B3, thus moving the block B4 at the same time along the slot b5 in the bar B5. As the guide in the bracket B3 is arranged at an angle to the slot b5 which is parallel to the line of sight, movement of the member b3 and the block B4 will angularly displace the bar B5 relatively to the sight arm B thereby imparting the desired vertical d'efiection to the sight. When the pointer (Z7 is in its zero position the aXis of the pin' b4 will coincide with the pivotal axis of the bracket B3 and consequently elevation of the gun will merely result in the cam rocking the bracket B3 without imparting vertical deflection to the sight. This rocking of the said bracket will vary the angle between the guide in the bracket and the slot b5 in the bar BG so that if the handwheel D4 is then operated the amount of vertical deflection imparted to the bar B5 will correspond not only to the vertical component of the relative speed of the tarV get but also to the height of the target and the angle of sight. If on the other hand thc member b3 has previously been adjusted by the handwheel D4 as aforesaid, the axis of the pin b4 will no longer coincide with the pivotal aXis of the bracket B3, so that if the gun be then elevated the pin b4 will operate as a crank pin upon the bar B5 during the rocking of the bracket B3 and the vertical deflection will be automatically varied for the height of the target and the angle of sight.

A similar arrangement to that described with reference to Fig. 4 can, as is the case with the arrangement shown by Figs. l and 2, be employed for automatically varying the horizontal deflection of the sight.

What we claim and desire to secure by Letters Patent of the United States is l. In sighting apparatus for anti-aircraft guns, the combination of means operating on the sight to set it for deflection to agree with the speed of the target relatively to the gun, and means, capable of adjustment in accordance with the ascertained height of the target also operating on the sight to automatically correct the said deflection setting of the sight for the changing angle of sight and for the changing range during the elevation and depression of the gun, without its being necessary to ascertain the range, and supporting means for said elements.

2. In sighting apparatus for anti-aircraft guns, the combination of means operating on the sight to set it for horizontal deflection to agree with the speed of the target relatively to the gun, and means, capable of adjustment in accordance with the ascertained height of the target also operating on the sight to automatically correct the said horizontal deflection setting of the sight for the changing angle of sight and for the changing range during the elevation and depression of the gun, without its being necessary to ascertain the range, and supporting means for said elements.

3. In sighting apparatus for anti-aircraft guns, the combination of means operating on the sight to set it for vertical deflection to agree with the speed of the target relatively to the gun, and means, capable of adjustment in accordance with the ascertained height of the target also operating on the sight to automatically correct the said vertical deflection se-tting of the sight for the changing angle of sight and for the changing range during the elevation and depression of the gun, without its being necessary to ascertain the range, and supporting means for said elements.

4. In sighting apparatus for anti-aircraft guns, the combination of means operating on the sight to set it for both horizontal and vertical deflection to agree with the speed of the target relatively to the gun, and means, capable of adjustment in accordance with the ascertained height of the target also operating on the sight toautomatically correct the said deflection settings of the sight for the changing angle of sight and for the changing range during theelevation and depression of the gun, without its being necessary to ascertain the range, and supporting means for said elements.

5. In sighting apparatus for anti-'aircraft guns, the combination with the sight arm and the sight, of a device interposed between said arm and sight for manually setting the sight for horizontal deflection to agree with the speed of the target relatively to the gun, a cam device capable of adjustment in accordance with the ascertained height of the target, and means, operated upon by said cam device, for automatically correcting the said horizontal deflection setting for the changing angle of sight and the changing range during the elevation and depression of the gun, without its being necessary to ascertain the range, and supporting means for said elements.

6. In sighting apparatus for anti-aircraft guns, the combination with the sight arm and the sight, of a device interposed between said arm and sight for manually setting the sight for vertical deflection to agree with the speed of the target relatively to the gun, a cam device capable of adjustment in accordance with the ascertained height of the target, and means, operated upon by said cam device for automatically correcting the said vertical deflection setting for the changing angle of sight and the changing range during the elevation and depression of the gun, without its being necessary to ascertain the range, and supporting means for said elements.

7. In sighting apparatus for anti-aircraft guns, the combination with the sight arm, and the sight bar, of a member mounted to slide longitudinally upon said sight arm, means capable of adjustment in accordance with the ascertained height of the target :for sliding said member during the elevation and depression of the gun, a bracket carried by said member, a second member mounted to slide on said bracket in a direction transverse to the direction of sliding movement of the iirst mentioned member and engaging with a guide in the sight bar, this guide being normally situated parallel to the direction of sliding movement of the irst mentioned member, and means for sliding the second membei1 in accordance with the speed of the target relatively to the gun, and supporting means for said elements.

8. In sighting apparatus for anti-aircraft guns, the combination with the sight arm, sightbar and the member carrying the sight bar, of a swinging bracket carried by said sight arm7 a member slidably mounted on said bracket and cooperating With a guide formed on a member carrying the sight bar, means for moving the first mentioned member in accordance with the speed of the target relatively to the gun, and means7 capable of adjustment in accordance with the ascertained height of the target, for rocking` said bracket automatically during the elevation and depression of the gun, and supporting means for said elements.

In testimony whereof We have hereunto aiixed our signa-tures.

ARTHUR TREVOR DAWSON. GEORGE THOMAS BUCKHAM. Vitnesses J No. R. CAsWELL, Gnn'rRUD-E VVHYTE.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. G. 

